:root {
    --bg-color: #f0f7f4; /* Soft light green / mint */
    --text-color: #2c3e50;
    --accent-color: #27ae60;
    --white: #ffffff;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    line-height: 1.6;
    overflow-x: hidden;
}

header {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 2rem;
}

.hero-image {
    width: 300px;
    height: auto;
    margin-bottom: 2rem;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
    transition: transform 0.3s ease;
}

.hero-image:hover {
    transform: translateY(-10px) rotate(2deg);
}

h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -1px;
}

p.subtitle {
    font-size: 1.2rem;
    color: #666;
    max-width: 600px;
    margin-bottom: 2rem;
}

.cta-button {
    background-color: var(--text-color);
    color: var(--white);
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.cta-button:hover {
    background-color: var(--accent-color);
    transform: scale(1.05);
}

section {
    max-width: 1000px;
    margin: 4rem auto;
    padding: 2rem;
    background: var(--white);
    border-radius: 20px;
    box-shadow: var(--shadow);
}

h2 {
    margin-bottom: 2rem;
    text-align: center;
}

.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.book-card {
    padding: 1rem;
    border-radius: 12px;
    text-align: center;
    border: 1px solid #eee;
    transition: border-color 0.3s ease;
}

.book-card:hover {
    border-color: var(--accent-color);
}

@media (max-width: 768px) {
    h1 {
        font-size: 2.5rem;
    }
    .hero-image {
        width: 250px;
    }
}